How effective self hypnosis is depends on you. It did not work for me but I am thinking of trying it again. A hypnotist tried to hypnotize me when I was in university and it did not work either. Personally I seem to be better at meditation. I am good at the relaxation part of hypnosis and guided meditation but I have trouble with the other suggestions.
I highly recommend trying meditation or self hypnosis so you learn how to become deeply relaxed. Like most things it takes practice.